Automatic control apparatus for spindles



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AUTOMATIC CONTROL APPARATUS FOR SPINDLES Aug. 13, 1963 R. N. KNosP ETALAUTOMATIC CONTROL APPARATUS FOR SPINDLES y 11 Sheets-Sheet 3 Filed Aug.22, 1960 INVENToRS.

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AUTOMATIC CONTROL APPARATUS FOR SPINDLES Filed Aug. 22. 1960 11Sheets-Sheet 5 Aug. 1.3, 1963 R. N. KNosP ETAL AUTOMATIC CONTROLAPPARATUS FOR SPTNDLES Filed Aug. 22, 1960 1l Sheets-Sheet 6 T u a w m 2W n Z 1 Z E 1 o Z Y w HHH 9 f Y 0V ,/a B uw m .H/HHHH AJHHHTWI.

Aug. 13, 1963 R. N. KNO'SP ETAL AUTOMATIC CONTROL APPARATUS FOR SPINDLES11 Sheets-Sheet '7 Filed Aug. 22, 1960 o o c o AWF ug. 13, 1963 R. N.KNosP ETAL 3,100,406

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AUTOMATIC CONTROL APPARATUS FOR SPINDLEs Filed Aug. 22, 1960 v 11sheets-sheet 9 as 35 4', l 4 34- 'f 1 s l IWB-TOM.

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AUTOMATIC CONTROL APPARATUS FOR sPTNDLEs Filed Aug. 22, 1960 11Sheets-Sheet 11 NUARMWNI A W a... mi m SN mi Y.MEQ umwu uww FEM o a N OmMN United States Patent() j 3,169,406 AUTMATIC vCtlulftli, APPARATUS FRf SPHNDLES j n Robert N. Knosp, Ludlow, Ky., and Donald l... Geeks,Cincinnati, (Bisio, assignors to The Fosdick Machine Tool Company,Cincinnati, (Ehio, a corporation of @hic vFiled Aug. 22, 1969, Ser. No..51,623

' 14 Claims. (Cl. 77-4) This invention relates generally to machinetools of the type having an axially movable tool spindle or thelike,`and is directed specifically to `an apparatus for controlling the axialspindle motion in an automatic manner.

The'present apparatus is disclosed in nelation Ato the quill and spindleof a vjig boring machine, which is used in machining operationsinvolving the precise location and machining of holes in 'a workpiece. Atypical jig boring machine of this character comprises a stationary bedhaving a saddle or cross slide which is shiftable along one coordinateor path of motion with respect to the bed, the saddle having a worktable which is slidable upon the saddle along a second coordinate atright angles to the first coordinate. The tool spindle is mounted on acolumn rising from the `bed and is adapted to advance the cutting toolaxially with respect to a workpiece which is clamped to the table, thehole center being alignedwith the tool axis by the combined movements ofthe saddle and table. v

In order to position the workpiece with a high degree of precision withnespect to the tool axis, a gauging and positioning apparatus, asdisclosed in Patent No..2,9`32, O88, issued to Robert N. Knosp, ione ofthe present applicants, is used to regulate the position of theV saddleand table.V As disclosed in the patent, the positioning mechanism of thetable and saddle may be regulated by a "ice slower, preselected feedrate to a predetermined depth,

thereby to save a great deal of time which would otherwith be consumedduring the spindle cycle of operation.

According Ito this aspect of the invention, axial spindle motion isregulated by a two-stage depth gaugingapparatus, the first stagemeasuring the distance of spindle travel at the rapid advancement rate`and the second stage measuring the spindle travel at the relativelyslow feed rate. In a given machining operation, the spindle resides inraretracted position at the start of the spindle cycle, and the degree ofrapid advancement is determined by the elevation of the top surface ofthe workpiece, the length of the cutting tool which is mounted in thespindle, and' other variable factors. By frea'son of these variables,the rapid `advancement gauging apparatus is arranged to, be reset fordifferent operations, such that the tool may be brought rapidly within asmall fraction of an inch above numerical control or programing systemin response to information which is rst Vsensed orread from a tape orthe like land transformed into electrical signals. These signals inturn, Vcause operation of motorcontrols which shift the slide yand tableto a retracted position, cause setsl of gauging rods to be shifted to anactive posit-ion, and finally cause the table and slide to be shiftedalong their coordinates until respective table and slide abutmentsengage the stackedI 'gauge nods, thereby-to locate the table and saddleeach at 'a final position vwith lthe hole center precisely aligned withthe tool` axis.

A numerical control system which providescomplete automatic regulationof .the functions of ia jig boring or other machine tool, is disclosedin the copeuding lapplication of Robert N. Knosp et al., Serial No.786,589, filed January 13, y1959. This `apparatus operating under tapecontrol or the like, regulates the gauging apparatus and the table andsl-ide motion noted above; it also provides automatic selection ofspindle speed rates, spindle feed rates, and automatic tool selection,for performing different types lof machining operations on a givenworkpiece.

One lof the importantiadviantages of the programing system of thischaracter arises in the speed at which the sequence of machine functionsis carried out. However, during any automatic machining opera-tion' ofthis character, a great deal 'of time is lost if the spindle must adv,vence and retractwith respect to the top ,surface'of the the surface ofthe workpiece iat the start of each spindle cycle; In a similar manner,the feed depth gauging apparatus is arranged to be reset in order toprovide for the thickness of the workpiece, or to determine the depth ofthe hole to be machined.

A fur-ther objective of the invention has been to provide a depthgauging apparatus which is adapted t0 be reset for :each spindle cycleby a numerical control system, whereby the degree of spindle travelatthe rapid advancement rate Iand lat the feed rate is brought aboutrapidly in an automatic manner in response to electrical signals whichrepresent the gauging digits.

Described generally, the gauging apparatus of this invention includesrespective sets fof stacked gauge rods, one

set providing the rapid advancement gauging and the second set providingthe feed depth gauging. The rapid advancement and feed depth gauge nodsare also referred to Ias shiftable gauging elements in the claims ofthis application. Inthe present example, the rapid advancement gaugingapparatus (firstV stage) consists of twosets of decimal gauge rods(shit-tablel gauging elements) graduated in increments of tenths vandhundredths of an inch, and coacting with a rotatable unit gauge orcarrier having `gauging surfaces graduated in increments of oneinch.Thus, the 'rapid advancement gauges may be set to provide spindleadvancement expressed as thnee digits, for example 5.85. The feedgauging apparatus (second stage) is provided with four sets of stackeddecimal gauge rods (shiftable gauging elements) graduated in lengths oftenths, hundredths, thousandths, and lten-thousandths of an inch. Thesestacked gauges `also coact with a rotaryvunit gauge which pnovidesgaugingsurface in- The rotary unit ygauges for the rapid advancement(first stage) and l[fee-d nates (second stage) are mounted parallel withone another and the related sets of decimal gauge rods are ycarried inrotatable turrets so arranged that the decimal rods lselected reside inend'wise align- (with the spindle retracted).

ment along a common axis which is :also common to respective stopelements of the car-riers. During `the indexing or gauging cycle, bothrotary one-inch gauge cariers are elevated to permit the turrets andvtheir decimal gauge rodsl to bev rotated to individual positionscorresponding to the digits signalled Iby the numerical control system,while the spindle resides in its retracted position. Thereafter, thefirst stage carrier is lowered to bring its stop into engagement withthe stacked ydecimal gauge rod's The second stage carrier is springbiased and remains elevated until a4 depth control rod, which moves withthe spindle, shiits it 4downwardly, as explained below. l ktiring thespindle cycle, the depth control rod, which Vfrom one tool to the next.

is connected to lthe quill, moves downwardly with the quill and spindlerelative to the Yselected gauge surfaces of the two one-inch carriers;the control rod includes a limit switch adapted to be tripped by theselected first stage one-inch gauge .carrier'and-the lower end of therod is adapted to abut the selected second stage carrier gauge.

During the quill `and spindle movement from the re tracted position, theaxial motion is imparted to the quill and spindle by ya rapid traversemotor; lwhen the rapid traverse limit switchiof the control rod enga-gesthe first stage carrier gauge, this motor isdeenergized and the spindlefeed continues at the slower feed rate (second stage) through operationof the feed transmission.

, At some point during the second stage, as determined v by the feedldepth setting, the end ofthe control rod engages the selected one-inchgauge of the second stage carnier and shifts the carrier |downwardlycounter to its spring. The rfeed gauge apparatus includes `a final limitswitch which is tripped at the second stage or depth limit. This switchdecommissions la magnetic clutch so as to rarrest the feeding motionprecisely at the preset feed depth. Thereafter, the rapid advance motoris energized in the reverse direction, so -as to shift thespindle andtool at the rapid rate back to the retracted position, thus ending Ythecycle for a given hole.` rIlhe numeral control apparatus thereafterrepositions the table and saddle to locate the next hole with respect tothe spindle axis, then the spindle cycle is repeated. i

During a sequence of automatic operations upon a workpiece, the numeralcontrol system will signal for e. tool change at the start of a spindlecycle, when the next hole so requires. In responseto the signal, themachine automatically ldisengages `the tool presently chucked in thespindle, and replaces it with the new tool, the tools being arranged ina predetermined numhered sequence. It will be understood that thevarious tools have standard lengths which may Vary considerably It has.been a further objective of the invention to provide a toolcompensating mechanism so arranged that themechanism readjustsautomatically for any difference in the length of the tool when a toolchange is-signalleid, whereby the spindle is advanced at the rapid rateuntil the end of the tool is'in closeproxirnity of the work surfacewithout regard to the length of the tool.`

It will be understood that the control tape is prepared in accordancewith the engineering drawings and other data, so kas toY provide the'machine functions in the required sequence. In preparing the tape fortool compensation, the length of the tool is taken into account buttheactwal length ofthe tool may vary Iby as much f advancement.V

In lgener'al, the tool compensating mechanism comprises a reversibletool compensating motor which is arranged to raise or lower the controlrod relative to the rapid advance and feed gauging apparatus. IIn the'present example, the apparatus includes an electrical circuit intenconnected with the compensating motor and including aV series ofadjustable potentiometers, one for each tool of the series, the motorbein-g in drivin-g connection with a feedback potentiometer. Thefeed-back and adjustable potentiometers are interconnected in a suitablecontrol circuit to create a servo-motor action, whereby the motoroperates in a direction tending to balance the values of the twopotentiometers, thus shifting the control rod in Y and the lengthnumerically coded on the tape. During d the appropriate direction. Afterthe each tool potentiometer is set manually at the machine so as tocompensate for the difference in actual tool length automatic operationthe compensating motor is energized automatically in the properldirection to raise or lower the control rod according to the valueprovided by the potentiometer -for that particular tool.

The various features and advantages of the invention Y will be moreclearly apparent to those skilled in the art from the following detaileddescription takenin conjunction with the drawings.

In the drawings: FIGUREI is a fragmentary plan view of the head of a jigboring machine incorporating the spindle control mechanism of thepresent invention.

FIGURE 2 is a fragmentary sectional view illustrating a developmentofthe dial drive and gauge carriers of the depth control apparatus,taken generally along line 2---2-` of FIGURE l. Y

FIGURE 3 is a fragmentary sectional View forming a continuation ofFIGURE 2 and s'howing the `remaining development of the controlapparatus.

FIGUREV 4 is a fragmentary sectional view of the upper portion of thequill broken away from FIGURE 2 and showin-g the tool compensating motordrive.

'FIGURE 5 is la diagrammatic perspective view, further illustrating thedepth control mechanism shown' in FIGURES 2 and 3. In this View, :aportion of the dial drive mechanism has been displaced transversely fromits true position, as indicated by the broken lines, in order to moreclearly illustrate the structure.V

FIGURE 6 is a sectional view taken yalong line t--6y of FIGURE 2,detailing the solenoid mechanism which locks the dial in a selectedposition during 'automatic tool depth selection.

FIGURE 7 is a view partially in section taken alongV FIGURE 9v is afragmentary sectional view Vof the finaliV limit switch and trippingmechanism which stops the quill feed at its downward limit of travel.y Y

FIGURE l0 is -a fragmentary sectional viewshowing i the safety switchwhich prevents energization of the dial motor until the gauge carrier isin its elevated position, thereby to permit rotation of the gaugecarriers.

. FIGURE 11 isa fragmentary view of the safety switchl Y las projectedfrom FIGURE l0'.

FIGURE k12 is a fragmentary view showing the dial` `at the lower limitof quill feed-v indicator which is tripped ing motion.

FIGUREV 13 isa yfragmentary perspective view of a jig boring machinewhich is provided with the spindle depth control mechanism of thepresent invention. y FIGURE 14 is a section as viewed along lin'e14S-14M of FIGURE 3, illustrating the crank mechanism and limit v switchwhich controls the raising yand lowering of the rapid advance ygaugecarrier. i

FIGURE 15 is an enlarged fragmentary sectional view,l taken from FIGURE2, detailing one of the decimal gauge turrets.

FIGURE 16 is a diagrammatic view showingfthe ratchet wheel whichregulates .the vertical motion' of i the rapid advancementl gaugecarrier.

FIGURES l7e20 are diagrammatic viewstillustrating-4 the spindle motionduring the tool length compensating cycle. Y

FIGURE 21 is a diagrammatic view illustrating thel drivingsystem forshifting the spindle at the rapid ad` vancement and feed rates.

tape is prepared, Y

ordinates 14 land 15.

d control circuit suitable for regulating the depth gauging apparatus.

General Arrangement and Operation As noted above, the depth control`apparatus of this invention utilizes the stacked measuring rodprinciple, generally similar to that shown in the prior Knosp et al.Patent No. 2,932,088. According to the prior patent, respective sets ofmeasuring rods or gauges are mounted in rotatable kdials which arerotated to shift selected rods into alignment Iwith one another toprovide a `given lineal dimension which precisely locates the table andcross slide from a given back-olf position to anew position in relationto the axis of the tool spindle. The present apparatus includes stackedsets of gauges or measuring rods adapted to control the feeding movementof the quill from a given retracted position to a final depth which isdetermined by the additive length of the selected measuring rods. l

Described generally with reference to FIGURE 13, the jig boring machineembodying the present depth control mechanism comprises a -bed 1, havingan upright column 2 rising from its rearward side. A drill head 3 isslidably mounted upon vertical ways (not shown) which are formed on thecolumn, adapting the head to be adjusted vertically with respect to thecolumn. A vertically slida-ble quill 4 passes through the head 3 andjournals a rotatable spindle y5 (FIGURE 17), the lower end of thespindle having `a chuck 6 which mounts the cutting tool 7. The spindle 5is rotated at a selected cutting speed by means of a speed changetransmission, as explained later, which is mounted upon the column abovethe heady 3, the spindle being in driving connection ywith thetransmission by means of `a splined shaft 8 (FIGURE 5). During amachining operation, the spindle rotates relative to the quill whileaxial feeding motion is imparted to the quill in response to the depthcontrol mechanism of this invention, as explained later lin detail. Thehead 3 includes a hand wheel 9 (FIGURE 13) which permits the quill to beadjusted vertically and is also provided with a small fine feed hand-wheel 1t). However, neither of these hand wheels is utilized when themachine is under control of the automatic depth control mechanism ofthis invention.

The workpiece, which is indicated generally at :11 (FIGURE 13) isclamped as atL 12 upon :a table I13 of convention-al construction. Thetable is mounted dor longitudinal motion, `as indicated by the iarrow14, upon a cross slide or saddle (not shown) which is slidably mountedupon the bed of fthe machine. The cross slide in turn is movable ,alongthe bed in a transverse direction, as indicated by the arrow 15. rIhus,prior to a machining operation, the workpiece is positioned with respectto the axis of the tool by the combined positioning movements of thecross slide yand table "ong the two co In the present example during oneof the operations under automatic control, the hole 16 of the workpieceis brought into alignment with the tool 7 which is 'arranged toper-torni la boring operation with respect to the hole to a depthregulated by the depth control mechanism.

During rautomatic operation, the position of the work is determinedprecisely by the positioning apparatus respectively lof the cross slide.and table .as disclosed in the aforesaid Knos-p Patent No. 2,932,088,which in turn, may :be regulated by the numerical control systemdisclosed lin the copending application lof Robert N. Knosp and DonaldL. Geeks, Serial No. 786,589, tiled January 13, 1959. The present depthcontrol apparatus is arranged to operate manually during initial .toolset up and is intended for 'automatic operation thereafter inconjunction with the above numerical control system ias one of theseveral machine functions which lare performed in predetermined orderunder control of a coded tap-e `or the like. In' other Words, after thepositioning cycle is completed, with the workpiece located in Workingposition with respect to the tool axis, and-latter other automaticmachine functions, such las tool selection, have been cornpleted, thenthe numerical contnol system signals the spindle .control :apparatus toinitiate the machining cycle. After the cycle is :thus initiated, thespindle control apparatus periorrns la sequence `of operations inpredeternxined order, Ias explained below, land thereafter sends asignal to the numerical control system, such that a succeeding machinefunction is initiated `aiiter the spindle has completed its operationand has retnacted to its starting position.

Upon initiation of the machining cycle, the spindle con-trol :apparatusadvances the cutting tool lat a rapid nate (first stage) during itsnon-cutting movement and at :a slower feed rate (second stage) :duringits cutting motion, s-o as to reduce the overall time for a givenmachining operation. Thus, when the depth control apparatus is regulated`antornatically by the numerical control system, the saddle and table,during a given cycle, are shiited along their two coordinates to locatethe hole center, While theV spindle and tool reside in the .retnactedposition. 'll-hereafter, when the numerical contnol system signals toinitiate t e machining cycle, the quill 15 is shifted downwardly at therapid rate to la predetermined plane above the Work surface (FlGURE 18).Ait this point, the rapid advance mechanism decommissioned and the feedmechlanism becomes effective to continue adyancing the tool in the samedirection, but at a slower feed nate during the machining operation(FIGURE 19). At the depth limit (FIGURE 20), the slow feed mechanism isdecommisstoned Iand the `tool is withdrawn from the Work back to itsretracted position at the napid rate. trol apparatus then signals thenumerical control system as noted above, in order to cause initiationlof the next machine function. f v

The dial drive mechanism, gauge carniers, and other components of thespindle control apparatus are mounted wit-hin a dial housing, which isindicated generally at 17' in FIGURES 1 and 13. The dial housing is,attached directly to the iront cf the drill head 3, adjacent the quill4, there being provided la depth control nod, indicated at 18, which isconnected to the quill so as to move axially with the quill relative tothe spindle control mechanism, as explained later in detail. As viewedin FIGURE l, the drill head includes la bearing` sleeve Ztl in which thequill 4 (not shown in this view) is slidably jour-nailed, the sleevehaving a T-slot 21 (FIGURE 1) receiving la series of nuts 22 forattachment 'of the housing 17. The opposite side of the housing 17 isattached tothe drill head by la series of bolts 23. The quill 4 thusmoves vertically with respect to the spindle control apparatus withinthe housing 17, the movements of the quill being transmitted to thecontrol apparatus through the rod 18, which is attached to the quill, asexplained later.

In iaddition to the rapid advance `and feed rates explained above, thepresent apparatus is also arranged to compensate for the length fof thetool which is mounted in the spindle chuck. For this purpose, the depthcontnol rod 1% may be shifted axially with respect to the by operationof a tool vlength compensating motor 24 (FIG- URE 4) which is inIdriving connection with a threaded upper portion 2.5 of the depthcontrol rod 18. The motor 24`is energized in forward for reversedirections, las explained later, so as to the depth control rod 18axially in 'accordance with yariations in the length of the differenttools which are nsed in sequence. The depth control rod 18 in tuincoacts first with the rapid tnaverse 'llhe spindle eonexposing theindicator face.

first stage gauges, while the tool tuavel lart the slower feed natte isgoverned by la set of second stage gauges.

Referring now to FIGURE 5, the rapid advance gauging apparatus (firststage), which is indicated generally at 26, is provided with la set ofthree dials and associated decimal and 'one-inch gauges lor shiftablegauging elements, indicated generally lait 27, which provideameasurement setting of three digits, for example 5.85, representlingltool travel from the fully retnacted position under rapid advance. p Thelower portion of the 'depth control roid 18 includes ia microswitchindicated at 28 (FIGURES 3 and 5) which is tripped by the rapid advancemechanism at the limit of eapid tolol laidvanoernent so as to out in the.slower feed mate as the tool approaches the work. For this purpose, therapid advance mechanism includes a rotary um't (one-inch) gauge carrier,indicated gener-ally at 30, which includes spinally arranged one-inch:gauge surfaces or abutments 31 engaged by the micnoswitch 28 inaccordance with the selected napid .advance dimension. These abutmentsprovide one-inch units lof measurement, while the ydecimal units areprovided by ygauge rod turrets, as explained later.

The depth control rod 1S also coacts with the feed gauging mechanism(second stage)v which is indicated generally at 32 in FIGURES 2 and 5.The feed gauging mechanism 32 includes a set of iive dials indicatedgenerally at 33 and associated gauges or shiftable gauging elements,which provide a measuring or gauge setting of ve digits, for example1.7682. The setting of the feed gauge mechanism deter-mines the distanceof tool travel at the slower feed rate after the switch 23 has beentripped at the limit of rapid spindle motion by the rapid advancegauging apparatus 26. For this purpose, the feed gauging apparatus alsois provided with a rotary one-inch gauge carrier, indicated generally at34, which is similar to the carrier 30 and which is mounted paralleltherewith. In this case, the carrier is spring biased upwardly andthe'lower end of the control rod 18 provides direct engagement with aselected gauge surface or abutment 35 of the carrier 34. Upon engagingthe selected gauge surface 35, the control rod shifts the carrier 34downwardly counter to its spring and this motion trips a nal limitswitch 36 (FIGURE 5). Upon being tripped, switch 36 decommissions thefeed drive and initiates the rapid advance or traverse drive in theopposite direction, so as to retract the tool from the hole. Whenthe'switch .36 is tripped, a dial indicator 37l (FIGURES and 13')V isalso tripped so as to indicate to the operator thatthe -machiningoperation is completed. It will be notedV that the abutments 35 `arealso spirally arranged similar to the rapid advance gauging apparatus,in order that they may be selectively placed in the. axial path ofmotion of the rod 18 in accordance with the selected depth dimension.The one-inch gauge carrier 34 also coacts with decimal gauge rodturrets, as described later.

It should be noted that the two sets of dials 27 and 33 have beendisplaced in FIGURE 5 for purposes of illustration; the dials actuallyare mounted upon a common shaft 38, as indicated by the broken line A inFIG- URE 5. Thus, the eight dials are disposed one above the other andare visible in the, Window 4t) (FIGURE 13) of the housing 17.

The dial' indicator 37 is mounted in an offset 41 in the lower Vportionof the housing 17 (FIGURE 13), the offset having a hinged cover 42 whichincludes a window tration, theY connection of the two shafts beingindicated by the broken line B `in FIGURE 5. l Y

Thenumerical control system forms no part of the The dials are rotatedtoV a number of different cutting tools are used for the seriesV ofoperations. Under numerical control, the toolsare placed sequentially inthe spindle chuck in `an automatic manner for each operation, thearrangement being such` that the window 46 (FIGURE 13) of the controlpanel indicates the number of the tool which is mounted in the chuckduring each operation. The control panel further includes two rotaryselector switches, indicated at 47 and 48, which may be manuallyoperated to select a tool independently of the numerical control systemwhen the machine is being set up. It will be noted that the selectorswitches provide for the selection of twenty different tools.

yOther manual operations are carried out by a plurality of push buttons.provides selective manual or automatic operation of the spindle controlapparatus. The adjacent push button 51 permits manual selection ofspindle depth control, that is, the distance the spindle travels atrapid advancement and at the feed rate. In manual operation, the sets ofdials 27 and 33 (FIGURE 5) are rotated to positions for setting thedecimal and one-inch gauges forV present example, the apparatus isarranged to select fromV a total of twenty tools. During initial set-upoperations, 'Y

these tool change cycles are initiated manually by depressing the toolchange push button switch 52 (FIGURE 13 depressing the push button S3.In manually setting up the machine, the compensating motor 24 may beenergized Y in forward or reverse directions by the compensating buttons54y and 55, thereby to raise or lower the spindle with respect to thesetting of the rapid advance gauging apparatus 27. Y

advance travel, feed travel, and feed rate into perforations or the likein the tape. In selecting the rapid travel distance, the length of thetool must be known within One-half inch. By way of example, if thelength of the toolis Aapproximately teny inches` in its working end, in

the retracted position, resides five inches above the surface of thework, the tape shouldbe punched to provide kapproximately fiveinchesrrapid traverse spindlelmotion.l Thus, if the actual length of thetool is nine and onehalf inches, that is one-half inch shorter,- thenthe ap' paratus would stop the rapid advance motion when the working endof the tool'is one-half inch above thek surface of the work.

In order to compensate -for this difference in tool length, thecompensating apparatus (motor 214) is adjusted on the machine as one ofthe set-up operations. Referring to FIGURES 17 and 18, which show thespindle in-its Thus push button 5t) (FIGURE 13) The spindle cycle-,maybe initiated manually by tion .under numerical control.

anodine retracted position, tlhe punched tape Vis -codedto advance thespindle and working end of the tool rapidly to the position indicated atC, which may represent one-half inch, as explained above. Since thespindie is fed at the slow feed rate after the-rapid advancement, agreat deal of time would be lost if compensation is not made for theclearance C. Therefore, the compensating motor is energized by hand(push buttons Se `and 55)1'11 the direction to raise the depth controlrod 13, -as shown in FIG- URE 19 causing the spindle and tool to shiftdownwardly and bringing the end of the tool to a plane which is a smallfraction of an inch above the surface of the lwork, as indicated at D.The slow feed rate is commissioned at this point, causing the tool tomachine the work until the depth control rod lli trips the selectedabutment 3S in the iinal limit (FlGURE 20) causing the tool to beretracted rapidly.

When initially setting up the machine for a number of tool changes, theapparatus is adjusted at the machine to compensate in this manner forthe length of each tool which is called for by the punched tape, so thatunder numerical control, the compensating cycle is carried outautomatically at .the beginning of each spindle cycle. According to thepresent example, the control system for the compensating motor 24 isprovided with a set of twenty ladjustable potentiometers, and the motoris in driving connection with a feed-back potentiometer, the circuitbeing such that a servo-motor action is brought about, causing Ithedepth control rod i3 to be raised or lowered in accordance with thesetting of the adjustable potentiometers.

As viewed in FIGURE 13, each potentiometer, which represents anindividual tool, is providedwith .an vadjustment head 56, adapting thepotentiometer to be adjusted with a suitable instiument. Thus, after agiven tool is mounted inthe chuck during a `set-up operation the spindleis fed downwardly at -t-he rapid advance rate (FIGURE 18), the operatorrotates the adjustment head 56 in the yappropriate direction to raise orlower the spindle (FG- URE 19). After this compensating adjustment hasbeen made lfor each tool, the ycompensating action is carried outautomatically upon each tool change during opera- Thus, no furtheradjustment need be made unlessit becomes necessary to sharpen one vormore of the tools,` causing a change in length.

Y 'Rapid Advancevand Feeal Depth Gauging Apparatus Aspointed out above,both the rapid advance gauging apparatus 26 (first stage) yand the feedgauging apparatus 32 (second stage) are indexed to gauging position bythe: dial motor i3 driving through suitable geartrains. The

position to which the individual dials 27 and 33 are rotated isydetermined by individual selector switches indicated generly at 57(FIGURES 2, 5, 22 and 23). In gener-al, each switch comprises astationary slip ring 5S (FIGURE and la commutator having a series of tenstationary contacts 59 concentric withrthe slip ring 5d.A

the electrical circuit tof FIGURES 22 and 23.

The ten contacts 59 correspond to the digits zero to nine of theindividual decimal dials.y vIn addition, there is provided twol selectorswitches for indexing the oneinch gauge carriers 3i) and 34 which are'provided by eight contacts, representing the digits zero to seven andcorresponding to The eight gaugingA positions of the 'carrie-rs. Thereis also provided one selector Switch having two contacts yforcontrolling the vertical movement` of the rapid advance one-inch gaugecarrier 30?.

Each selector switch further includes a brush6ii (FlG- URES 2 and 5)which establishes a bridging circuit between the ring and contacts so asto complete an electrical circuit which causes the gauges to be stoppedat their preselected positions, -in general, during dial selection onecontact S9 of each selector switch is energized by the programingapparatus, the arrangement being such that when the circuit is completedbetween the energized contact and slip ring by the brush 60, a circuitis completed to an associated solenoid 6l (FIGURES 6 and 7), which stopsthe dials at the selected position, as explained later with reference tothe electrical circuit. The construction and operation of the dial drivemechanism is described in detail later.

As explained earlier with refe-rence to FIGURE 5, the rapid traversegauging apparatus (first stage) comprises two sets of decimal gauge rods(shiftable gauging elements) and a one-inch abutment carrier previouslyindicated at 39, upon which the gauging surfaces or abutments 3d arespirally arranged. The abutments are serially located in alignment withthe microswitch by rotary stepwise adjustment of the carrier 30. The rstabutment 31 (gauge surface) Ia-t the top represents zero, the remainingabutments increasing in steps of one inch, such that the lowermostabutment provides a measurement of seven inches. The first set ofstacked decimal gauges or rods (shiftable gauging elements), indicatedat 62 is arranged in a series of ten, the shortest rod representingzero, the remaining rods increasing in steps of one-tenth, such that thelongest rod provides a measurement of ninetenths lof an inch (FIGURES 3and 5 The second set of stacked decimal gauge rods (shiftable gaugingelements) indicatedat 63, is also arranged in a series of ten, theshortest rod representing zero, the remaining rods increasing in stepsof oneehundredth of an inch each, the longest rod representingnine-hundreths of `an inch. In the present example, the rapid advancegauging apparatus (lirst stage) provides a maximum measurement ci 7.99.

The two sets of decirnial gauge rods are carried in rotatable turretsindicated at 64-64 (FIGURES 2, 3, 5 and l5) which Iare rotatablyjournalled upon a turret shaft 65. The turrets are thus mounted upon acommon axis of rotation and the individual gauging rods (shiftablegauging elements) reside in a ycircle which passes through an axiscommon to the two rapid Iadvance abutment studs 66 and 67. The vupperabutment stud 66 is carried by the, one-inch gauge carrier` 3i) and thelower abutment stud 67 is mounted in a flange 63 formed in the housingi7, the two studs being mounted upon a common axis. n

v In order -t-o permit the vfirst stage stacked decimal gauges 62 and 63(shiftab-le gauging elements) to be indexed to "a selected measurement,the one-inch gauge carrier 3i)1 is shifted at the beginning of a cycleto an elevated position, as shown in FIGURES 3 land 5 so as to provide amaximum spacing between the abutment rods 66 4and 67. This spacing isslightly greater than the maximum measurement 7.99", the dimension beingsuch that a slight anion-ntof clearance exists between the ends of thestacked gauge rods when they are shifted to the maximum measurement.

During the measuring cycle, the rapid tnaverse oneinch gauge carrier 3Gis` iirst shifted to the elevated posi-n tion shown in FIGURES 3 and 5,then the dialsfgauge rods, and 1one-inch gauge carrier `are notated toprovide a dimension as signalled by the numerical control system;thereafter, the carrier is shifted downwardly to bring ,the abutmentstuds 66 and 67 into endwise abutment With gauge rods or shift-ablegauging elements arranged .in four individual sets in the-order ortenths, hundredths, thousandths, and ten-thousandths of an inch. Thesestacked ll decimal gauge rods (shiftable gauging elements) coact withthe one-inch abutments (gauging surfaces) 3S `of the carrier 34. In thepresent example, the one-inch abutk ments'and the decimal rods larearranged to provide a maximum dimension of 7.999. The tenth rods,indicated Iat 69 (FIGURES 2 and 5) are arranged 1n a serres of ten, theshortest rod representing zero land the length of the rods increasing intenths of an inch, the longest rod, which is shown indexed to itsmeasuring po'srtron, representing nine-tenths of Ian inch. The remainingsets of rods 70, 71 and 72 fare similarly arranged respectively inincrements of one-hundredths, one-thousandth and one tenathousandth ofan inch. These gauges similar to the rapid traverse gauges, `are mountedin turrets indicated at 73, 74, 75 Iand 76 which are loosely journalledupon ,a second turret shaft, indicated at 77. The turret shafts 65 and77 are shown in FIGURES 2 and 3 and the relationship of the two shaftsis best shown in FIGURE 1. .The feed 'depth dimension (second stage) isselected, similar to the rapid advance ldimension (first stage), byrotating the turrets individually to bring the selected gauge rods(shiftable gauging elements) in stacked relationship in alignment with apair of abutment studs 78 and 80, .the upper-stud 7 8 being mounted uponthe gauge carrier 34 and the lower `abutment stud or feeler Sti (FIGURES2, and 9) being mounted in a lever 81 which operates the limit switch36, 4at the lower limit of tool travel.

The yone-inch feed gauge carriert` (second stage) is normally biased toan elevated position by means of a spring 82 (FIGURE 2) so as toprovidespacing between the `abutments 78 and 89 which is slightly greater thanthe. length of the maximum measurement (7.999) to permit rotation of theturrets and rotary abutments (gauging surfaces) 35 to selectedpositions. The gauge carrier remains in the elevated position until theend o-f the depth control rod. 18 engages the selected one-inch abutmentand shifts the carrier downwardly toward nal spindle position. l y

It will be recalled at this point, that the tool is advanced in therapid rate until the rapid .traverse switch 28 is tripped by the rapidtraverse labutment (gauging surface) 31; it will also be recalledthatthe spindle continues at the slower feed rate until the lower end ofthe depth control ric'd 18 engages the selected. `abutment (gaugingsurface) 35 of carrier-34;. As the carrier 3d approaches final positionthrough operation of rod 18, the upper abutment.

.stud V'iti-forces the stacked decimal gauges downwardly, thusdepressing the lower feeler rod or abutment stud 301,

' thereby lactuating the lever S1 and tripping the ilimit Yinclude. agear turret 83 keyed thereto for rotating the turrets to measuringposition. The sets of gauge rods (shiftable gauging elements) yareslidabl-y mounted in` respective bores 8dpassing through the turrets andgears S3. Each rod .is grooved as at 35 'and has a split ring v86 seatedin the groove. A compression spring 87 has its 'lower end seated uponthe gear 83 audits upper end engaged against the split ring. 'IheVsprings thus hold the gauge pods in elevated posit-ion and adapts themto be shifted downwardly into engagement with thelower ialbutrnent studwhen the measurement is made. The turret shaft 65 .is non-rctatable, itsupper end being mounted in the top 'wall of the housing 17 and its lowerend being confine-d in a blind hole formed in the flange within theVhousing 17. The shaft includes a shoulder 88 bearing `against `the upperturret to hold the turrets in yaxial position along the shaft.

The rapid traverse (first stage) gauge carrier', indicated lat 3h(FIGURES 3 and 5), comprises a sleeve 9o slidably mounted as at 91 upona pair of shafts 92-92 for vertical movement. The carrier includes upperand lower cross pieces 93-93 extending lacross the ends of the sleeve99, the upper abutment 66 being carried in a block 94 mounted upon theupper cnoss piece 93. The spirally arranged gauging surfaces oriabutment 'blocks 31 each form la part of respective collars 95, thecollars being stacked upon a shaft 96 having upper and ilower endsjournalled as at 97-97 in the upper iand lower cross pieces. The lowerend of the shaft 9S includes` a fixed collar 98 and its upper endincludes a threaded collar-189.

The xed collar rests upon a shoulder 101 formed onV shaft 96, while thethreaded collar clamps the stacked collars oneupon another, with theabutments (gauging surfaces) 31 spirally arranged so that the rabutmentsmay be selectively indexed into alignment with the limit switch 2S byrotating the shaft 95. For Vthis purpose, there is fixed to the lowerend of shaft 96 a gear 162 which meshes with the dial gear train, asexplained later.

It is to -be noted at this point, that the first stage carrier Si)@FIGURE 3) is shown in its elevated position for indexing the turretsand Vabutment'carrier with its upper end engaging a boss I99, its lowerlimit of travel being shown by the position of gear 102 in broken lines.During the indexing cycle, the carrier 3o is first shifted to theelevatedposition by a crank pin 193 (FIGURES 3 and I4) which is rotatedVby the dial drivingV system as explained later.' Crank pin 103 includesa link i0@ having a lower end which is journalled upon a pin 105.

The pin is mounted in 'a block which is attached to the lower crosspiece 93 of carrier 39. The link 104 isV slotted to permit downwardmovement of thelink independently of the carrier 39.

During the indexing cycle, the dial motor 4.3,.through controlapparatuscauses rotationof the crank pin 103 rto 'Y its lowered positionso ras to lower the carrier 3G' and abutment stud 66 into engagementwith the stacked gauge rods or shiftable gauging elements. Rotation ofthe crank is halted by la second limitswit'ch 107 when the 'crank pin193 reaches its lowermost position. As seen in FIG- URE 14, the crankpin 193 is mouuted'upon a disk 198 which is carried -by a shaft 11o, thefdisk having a notch I lll which trips the switch 107 in the loweredposition of the carrier.

This operation is described in tail later with reference to the controlcircuit.

The feed gauging turrets 73-75 (second stage) lare similar to the yrapidadvance turrets and the turret shaft 77 (FIGURE 2) is mounted in thehousing in ia manner similar to the `shaft 65. Each turret is alsoprovided with a turret gear 83 for rotating the decimal gauge rods(shiftable gauging elements) to selected positions. The onegreaterdeinch gauge carrier 34 is similar to the gauge carrier lith includingthe sleeve 9i), upper and lower cross pieces 92,

and 93 androtatable shaft 96 upon which the one-inch Y abutments 35(gauging surfaces) are spirally arranged for selection upon rotation ofa gear 113. The sleeve 9tl'is slidablymounted upon a pair of shaftslitt, similar to the shafts 92-92- Y .f

g As'noted earlier, the second stage carrier 34 is spring biasedupwardly by a tension spring 82. (FIGURE 2) havl ing its upper endanchored to a stud M5 projecting fromthe housing wall. The lower end-ofthe spring isan-V chored to a stud `ilo projecting from the lower crosspiece 92-of the carrier. VWhen the spindle is in its retracted position,the spring shifts the carrier upwardly into enlSwitch i106 is mounted.on a bracket l112 within 13 gagement with the end of la boss similar toboss 99 of FIGURE 3, suchV that the upper cross piece 93 trips a limitswitch 117. The limit switch 117 is mounted on a bracket 117a Withinhousing 17 (FIGURES l() and 11) and is tripped by an angle piece119attached to the carrier 34. This'limit switch is also inserted in thecontrol circuit to permit rotation of the turrets only when the lcarrier 34 is in its upper position to provide clearance between theupper and lower abutment studs 7S and 8i! for turret rotation. As thespindle and tool as a unit moves downwardly, the end of the depthcontrol rod 18 .engages the selected abutment 35 and thus shifts thecarrier downwardly, causing the upper abutment stud 78 to act throughthe stacked gauge rods (shiftable gauging elements) against the lowerabutment stud Si?, thereby to trip the limit switch 36. The maximumdownward position of the carrier is indicated by the broken lineposition of lthe gear -1'13 (FIGURE 2).

Dial Drive Mechanism As noted earlier, the gauge rods and abutments forthe rapid advance and feed motion of the spindle are rotated to theselected position by the dial motor 43, which is in direct drivingconnection withrthe shaft 44 (FGURES 1-5 and 15). Shaft 44 includes laseries of clutch gears 11S which provide a driving connection to theturret gears rS3 iwhich [drive the decimal turrets r645-65 and 7S-76 ofthe rapid traverse and feed depth gauging rods. The clutch-gears 118 ofshaft 44 are also in driving connectionwith the rotary abutment carriers3@ amd64, and with individual gears 120 which form a part of theselector switches 57 and fdials 2.7 and 33.y

These switches, as explained later, energize the solenoids `61 (FIGURES6 and 7) which stop the individual dials and turrets in the selectedpositions. For this purpose, each of the clutch gears 118 is infrictionial driving connection with the motor shaft 44, adapting theshaft to continue to rotate as the individual dials and associatedturrets are stopped in selected positions. ln addition to thefrictional'ly driven clutch gears 118 for the rapid traverse and feeddepth gauge rods and abutments, there is also provided a frictionallydriven clutch gear 121 (FIG- URES Z and 16) which raises and lowers therapid tral verse abutment lcarrier 30 during the spindle cycle, asexplained later.

As noted earlier, the dial driving system is shown in developed forrnvinFIGURES 2 and 3, the second stage feed depth decimal turrets andone-inch carrier being shown in FIGURE 2 and-the first stage rapidadvance decimal dials and one-inch carrier *being shown on Flr-Y URE 3as a continuation of FIGURE 2. The dial driving shaft 44, which isjournalled in ball bearings 419-49 of the housing 17, is also shown inbroken lines in FIGURE 3 to complete the drive to the rapid traversedial'sand oneinch abutment-carrier. The truevrelative location of theseveral shafts and other components'isshown in FIG- URE 1.

Y Referring now to FIGURES 6 and '7, each clutch gear 11S is rotatablymounted'upon a sleeve `122 which is keyed to the shaft 44 and eachclutch gear 118 meshes (FIGURE 1) with a respective turret gear 83 ofshaft 77 and also with a respective selector switch gear 120 of shaft123. During rotation` of the shaft 44 by the dial lmotor, the decimalturrets and abutment carriers are rotated until they are stoppedindividually at selected positions by the individual solenoids 61, onesolenoid being provided for each dial; there is also provided a solenoidfor the gear y121 which raises and lowers the rapid traverse gaugecarrier 3G (FiGURE 16). Rotation of shaft 44 continues un-til the lastselector switch of the series, including thecarrier gear 121, hasbeen-rotated to the position determined by its energized contact;ythereafter, the spindle cycle is initiated, as explained-with referenceto the circuit diagram.

kDescribed in detail (FIGURES 6 and 7), each selector rodeos gear 11Sincludes a ratchet disk -124which is pinned as at for rotation with thegear. The sleeve 122. is keyed as at `126 to shaft d4, and each sleeveincludes a flange 127 at its lower end. The selector gear 118-frictionally engages a ring 128 carried by ilange 127, the gear beingurged against the friction ring by a spring-loaded plug 13d. Plug 13h ismounted in a bore formed in a holder 131 which is threaded as at 132upon the upper portion of sleeve 122. A compression spring 133 is seatedwithin the cap 131 and urges the plug 130 against the upper surface ofthe ratchet wheel 124. Accordingly, the gear 11S rotates with shaft 44in the direction indicated in FG- URE `6 until the ratchet wheel islatched against further rotation by the associated solenoid 61.

Each solenoid is mounted upon an adjustment plate 134 having one endpivotally connected asat 135 for adjusting motion about the taxis ofshaft d4, and having a shiftable end 136 adjacent a pair of adjustmentshafts 137- 1137. The plates 13dr are locked in adjusted position byrespective pairs of nuts 138--133 threaded on the shafts r1337. Eachsolenoid 61 is mounted upon the adjustment plate 13d by means of anangle bracket 14) (FIGURES 6 and 7) and each solenoid includes anarmature 14,1, which is pivotally connected to a latching finger 143.The latching yfinger is pivotally carried by a stud 1de rising fromplate 134 and includes a pawl 145 arranged to engage the teeth 146 ofthe ratchet wheel 124. The latching Enger 143 is normally held in aretracted position by a compression spring 147 having one end seatedagainst` an abutmentV member 148 attached to the plate 134. The oppositeend of spring 147 is seated against a lever 156 which forms a part ofthelatching finger 143. A headed screw 149 forms a stop 'which limits themotion of lever 150, as indicated by the broken lines.

When the solenoid 61 is de'energized, the compression spring 117shiftsthe pawl 145 to a retracted position with respect to the ratchet teeth,thus permitting the gear `118 to be rotated and to rotate the decimalturrets and selector switches to their selected positions, as signalledby the numerical control system. When the energized contact 59 of therespective selector switches are traversed by the associated brushes611, the solenoid for that dial is energized, thus shifting the pawl tothe position shown in FIGURE 6 to arrest the gear 118 in the selectedposition of the dial. It will be noted that the solenoid and ratchetmechanism for the t-Wo rapid advance turrets (first stage) Iand for thefour feed turrets (second stage) are identical to the structure shown inFIGURES 6 and 7. It is also to be noted that, the ratchet wheel 124 isprovided with six teeth, while the turrets are each provided with tenmeasuring positions; however, the ratio between the gear trains, asdescribed below, provides the advancement of one gauge rod uponadvancement of one tooth of the ratchet wheel 124. The two teeth of theratchet wheel 1245i (FIGURE 16) provide the up and down positions of thecarrier 3l? through the ratio of the gear train.

As noted above,.the rotary abutment carriers 30 and 34 are also rotatedto selected positions under the control of solenoid-actuated selectormechanismsas shown in FIGURES 6 and 7. It will be recalled that theabutment carriers 3@ `and 34 are rotated to eight selected positions,[representing one-inch gauging positions from zero to seven for eachrotary position. The ratchet wheels for the abutment selectors are eachprovided with six teeth land the gear ratio between the dial shaft 44and abutment carriers is arranged to provide one-eighth revolution foreach one-sixth revolution of the ratchet wheel to properly indexj the[abutment carriers. i

Referring to FIGURES 3 and 5, the rapid advance (first stage) decimalturrets 64 are driven from the dial shaft de by respective gears 151 and152 which are mounted on the countershaft 153i and which rnesh Iwith theturret gears `83. The driving'train is completed to the clutch gears 118of the dial shaft 4dby the gears l15d and 155,

which are mounted on a second countershaft 156. Both countersh-afts arerotatably journalled in hall bearings gear 154 to pinion 158 which ispinned as at 166 to countershaft 153, and from the countershaft to gear151, also pinned to the countershaft `153'. The upper turret 64 isrotated to its selected position by a gear 161 which is pinned to thecountershaft 156, and meshing with one of the clutch gears 118 of thedial shaft 44. The drive is completed by way of the gear 155, alsopinned to the countershaft `156 and through pinion 152, which is looselyjournalled on countershaft 153 to the gear 83 of the turret 64.

The Aabutment carrier 30 is driven from its clutch gear 118 (FIGURE 3)by an idler gear 162loo-sely journalied on countershaft 156 and meshingwith an idler gear `163 pinned on the c-ountershaft 153. Gear 163includes a pinion 163a which meshes with a gear 164,

as indicated by the broken lines, loosely journalled onY theoountershaft 16S. Gear 164 is confined againstendwise mot-ion by collars156 which are pinned to the countershaft 165. Although gear 164 andcountershaft 165 are shown displaced, the countershiaft 165 is mountedadjacent countershaft 153, adapting the .gears to mesh. The idler gear164 meshes with a drive gear 167 which is pinned to a countershaft 158which is journalled in ball bearings 157. The lower en-d of countershaft16S includes :an elongated gear 17d pinned to the shaft and meshing withthe gear 102 (shown in broken lines) .which is pinned to the lower endof the one-inch gauge shaft 96, as shown on the left side of FIGURE 3,thus cornpleting the driving train from the clutch gear 115 of the dial'drive shaft to the abutment carrier 3); The Velongated gear 171iladapts the rapid advance abutment carrier 30 4to be shifted to theelevated position shown in full lines in FIGURE 3, while its` drivinggear 1412 remains in mesh with gear 17d'.

Referring now to FIGURES 2 and 5 the feed depth turrets 73-76 (secondstage) are mounted on shaft 77 which is located adjacent the dial shaft44 (FIGURE l) Y clutch gears 113 which meshes with an idler gear 171.

which is loosely journalled on the countershaft 156 (FIG- URE 3). Idler171 drives an idler 169 on shaft 153 and includes a pinion 169m TheIpinion 16951 in turn, meshes with .a -driving gear 172 pinned to theshaft 173, which is journalled on ball bearings 157 parallel with theshaft 168i. An elongated gear 174 is pinned to the lower portion ofshaft 173 and meshes with the .gear 113 which is pinned to the lowerend'of the one-inch carrier shaft 96 of the feed gauge mechanism 32. Theelongated gear 174 land' gear 113 'are shown at the upper end of thegauging apparatus in FIGURE 5 for purposes of illustration; however, itstrue position is shown in FIGURE 3.

The shaft 173` includ-es at its lower end an adjustment knob 175 formanual setting of the one-inch abutments or gauging surfaces 35. Theshaft further includesa notched disk 176 coacting with 1a limitsw-itch177.. The `limit switch forms no part of the control circuit and hasbeen omitted from thecircuit diagrams.

As best shown in FIGURE 3, the crank pin 103 is driven fromV thelowermo'st clutch gear 121 by an idler gear 17Srotatably journalled on astubshaft 180. Gear A178 meshes with agear1S1 which is pinned to a shaftcarrier 3d is controlled by the limit switches 166 and 107, as explainedlater. j

. T ool Compensatzng M echansm Described with reference to FIGURES 4 and5, the

tool compensating motor 24 is mounted on a housing or stop collar 186attached to the upper portion of the quill, and is in driving connectionwith the threaded upper end 25 of the depth-control rod 18. As notedearlier,

the rod 18 projects downwardly into the housing .1&7V

(FIGURE 13) for. coaction with thefeed and. rapid ad- Vance` gaugingmechanisms. Y As shown in FIGURE 2', the lower end of rod 118 includes agui-deblock 1&7: slid-- ably mounted upon a pair of .guide rods 188(FIGURE l), the limit switch 28 being mounted' upon a bracket 19d whichis attached to the guide block 187. The switch 23 isV thus shifted alongan'acrcurate path with respect to` the one-inch gauges 35.

As viewed in FIGURE 4, the stop collar 186 includes a gear housing 191,the motor 24 being attached to the hou-sing by screws 192. A gear 193 iskeyed Vto the moto-r shaft and meshes` with -a pinion y194, which isrotatably journalled on ball bearings 195 within the gear housing. Thelower sleeve portion of pinion 194 is counterbored as at 196 to provideclearance about the rod- 18. A sleeve 197 projects upwardly as a partofpinion 194 and forms a nut in threaded eng-agement with the threadedportion of control rod 181. Operation of motor 24 thus rotates thesleeve 197, causing Vthe control rod 18 to be raised or lowered, the rodbeing held against rota- V tion by the guide block 157.

In order to prevent excessive l-ooseness in the screw threads, the nut197 .includes an anti-backlash nut- 198,

which is also engaged on the screw threaded portion 25 Spindle DrivingSystem The spindle drive mechanism does not form a part of the presentinvention; however, the structure is disclosed diagrammatically inFIGURE 2l. The axial feeding motion is imparted to the spindle by thefeed box trans.-

mission, indicated at 205, which is powered by the shaft 206. Shaft 256is in driving connection with the spindle speed transmission, so as torelate the axial feeding motion Y with the spindle speed.

The feed box includes an output shaft 207 which includes a bevel gear2118 meshing with the bevel gear 210 mounted on the Vertical shaft 211.Shaft 211 includes at its lower end la bevel gear 21.2 meshing with abevel gear 213 of horizontal shaft 214'. The horizontal shaft 214includes a worm 215 which drives a worm wheel 216 mounted on the spindleclutchV shaft 217. As seen in FIGURE 8, clutch shaft 217 includes apinion 21Sv meshing with a rack 221i. The rack is connected to the quilland thus transmits the feeding motion of the feed boX to the quill. l Yy In order to provide rapid advancement of the quill and spindle, thereis provided a reversible rapid traverse motor 221 belted as at 222 to apulley 223 keyed to the vertical shaft 211. The motor is powered by thelines 224. Shaft 207 includes an electrically operated rapid traverseclutch 225, controlledvvby the lines. 226,'the clutch being worm 215`for feeding the quill while the rapid traverse The . t 17"1 fmotor2`21.idles. electrically' operated spindlelimit clutch 227 is alsolinterposed inthe vertical shaft to decommission the `driving connectionat the nal linnt of spindle travel. This clutch is of conventionaldesign and includes electricallyfcontrolled friction plates indicateddiagrammatica-llyat. 228 in FIGURE 8.

1 `At the startof an operatingl cycle, with the spindle in i-tsretracted position,V motor 221 is energized in a direction to advancethe quill and spindle at the rapid rate under the control vof 'limitswitch 28, asindicated in'FIGURE 18. During therapid advancement, thefeed clutch I225fis disengaged to permit rotation of shaft 207independently of the feed box.A The limit clutch 227 is engaged during tThe several power units are energized by way of the power lines 243.

As noted with reference to FIGURES 17-20, the spindle resides in arretracted position at theV start of a spindle cycle. The control circuitincludes a spindle actuated switch 244 which is mounted in the head` andarranged to complete a control circuit in the retracted position of thespindle. lt will be noted in FIGURE 22 that the leads 245 from the'Astorage unit 242 eachrepresent ten individual lines 146'which energizeone selected contact of each decimal selectorA switch 57, both of the`feed depth group (FIG- URE 22) vand'of the rapid advance group (FIGURE23).

the rapid ,traverse and feed `advancement of the quill.

When the limit switch 28 is tripped, the circuit deenergizes the motor'2.211l and engages clutch 225, such that they feeding continues inthesarne directionY but at the feed drawn` towardthe limit switch'by 'atension spring 232, the lever 81 includes an adjustment screw 233 forprecise adjustmentof the apparatus. v f y There is also provided asafety'switch 234 (FIGURE 9) which is mounted-above the leverfSl 'inapositionto One of the lines 245 also energizes one of the eightcontacts of the one-inch carrier switches which are indicated at 247-247in FIGURES 22 and 23.A As explained earlier, thedecimal selectorswitches 57 are each provided with ten contacts representing the digitsfrom zero to nine,

rwhile the one-inch selector switches 247 are provided with eightcontacts; representing the digits from zero to seven.

' provides a cushioning effect. The lever 81 is normally v be trippedshould the spindle overtravel its preselected depthth-rough amalfunction of the apparatus. The swingingend of the lever is providedwith a second adjustment screw 235 which engages the plunger of theswitch upon overtravel.V Y p j s, Referring to'FIGURES l, 9 and l2, thelever 81 is non-` rotatably attached to the rock shaft 230, the oppositeends of the shaft being journalled in anti-friction bearings 236-236(FIGURE l); The end of rock shaft 2341 ,k op- All lof the selectorswitches are shown with the respective brushes 60 in the zero position.The selector switch indicated at 248 (FIGURE 23) represents thetwo-position switch which controls the up and down position of the rapidadvance one-inch carrier 30.

It will be recalled that it is necessary for both the.

lone-inch 'rapid ltraverse carrier 30 (first stage) and oneinch Ifeedcarrier` 34 (second stage) to be shifted to the elevated position beforethe ydials and turrets are indexed, in order to provide clearance forthe stacked decimal gauge rods (shiftable gauging elements) between theabutment studs. The -safety switch 117 of the feed carrier 34 is tripped-at this time `because the spindle is retracted and the vcarrier iselevated by its spring. This switch is interconnectedin the controlcircuit by way of line 249 to signal the up position of the carrier. Atthe start of the cycle, a circuit is alsocompleted from the memorystorage.

unit by way of Vline250 to the upper contact 59 of the one-inch rapidadvance carrier switch 248 (FIGURE 23), such that ther solenoid 61 ofthe two-position 'switch is deenergized (line 252) to hold carrier 30 inits elevated position. The dial motor 43 is also energized -at thistime. During this operation, the brushes of theorie-inch posite lever81, includes a short lever 237 (FIGURE Vl2) v clarnped'as Iat 238 to therockA shaft. The outer end of lever 237 includes a pin 240 which engagesthe actuating element 241 of -the 4dial indicator 37. VThe element 241permits the indicator to be set -to a givenl reading so as to providea'rreading ofthe accuracy of tool feed'at the end of thefeed cycle. l i

Gauge Selector Cz'rc-Ltz'z-lr1ftltd Operation As pointed-out earlier,the electrical circuit for regulating the depth gauge apparatus does notform a part 'of the invention; however, in order tomore clearlydisclosethe" operation and sequence of the spindle cycle, a simplifiedelectrical circuit is shown in FIGURES 22 ar1d'23.` These views havebeen placed upon two sheets of drawings in order torprovidethe-necessary: space, the horizontal leads of the two` views beingaligned with oneanother in order to more readily follow thefcircuits.'yf .Y l

The box labled main control circuit jreprsents. the

i prograrningosystem disclosed in the aforesaid Knospj et al.

application SerialNo. 786,589-which provides electrical signalsgenerated by the reader 239 in accordancewith coded information `carriedby Ia punched tape or the like.` As shown in the diagram, the readersignalsv are transmitted to a` memory storage unit 242. `Themain-control circuit, whichrrepresents the entire numericalcontrolsystem, is adapted to automatically controlI the table Tand`ksaddle position, the rate of spindle feed (feed box 20S- FIGURE 2l),and the rate of spindle'rotation as disclosed inthe aforesaid copendingapplication; the main control also `regulates the spindle cycle, toollengthcornpensation and spindle cycle of the present applicationunder'tape control'.

and decimal selectorswitches 57 are held in stationary position byoperation of the friction clutches, theirsolenoids'61 being energized(line 251), the pawls being engaged with the: ratchet teeth.(FIGURE 6).

, Wlhen the carrier 30 lis in.l its elevated position,the

` br-,ush'of carrier switch I248 completes a circuit from its uppercontact, line 252, through the brush line l253, lwhich ysignalsfthe maincont-ncl circuit that the. carrier is elevated. l The control Vcircuitin turn sends `a signal by way of line 254 `to kthe solenoidyl whichregula-tes switch 24.8,

thus energizing the solenoid and engaging the pawl so astoyhold'thecrank pin 2103 `and switch in the upy position.-v The ysolenoid circuitis completed by way of line 255 which is common to all of the solenoids.AThe cars -rier 30" also tripsits upwlimit switch 106' (FIGURE 3) thuscomple-ting a circuit from line 256 to line 257 which isinterconnectedin the main control lcircuit to signal the u'p position of carrier 30. oy Y g In .response to switch 1016, the main control circuit deenergizesthe solenoids 6l lfor :the ydecimal lone-inch selecf tor switches, whilekeeping the, solenoid of the two-position 'selector switch 248energized; thus permitting rotation of the brushes `60 of the one-inchselector Switches l l247 and decimal switches 57. VThe memory storageunit 2,42 'now .energiz/es one contact 59 4of each switch by way ojflines 245 Iand branch lines 246,- so as to select the required one-inch,and decimal gauges.l As the respective lbrushes 60 engage the energizedcontact of each switch, they complete a circuit back to the main controlcircuit' Vby way of .the lines 253, which lead from the brushes. As'each of these lines" is energized, the main cont-rol circuit lenergizesthe respective lines 251 which lead to the solenoids ktil of theindividual switches, the 'i of the spindle control apparatus

1. A CONTROL APPARATUS FOR REGULATING THE AXIAL MOTION OF A TOOLSPINDLE, SAID SPINDLE HAVING POWER MEANS FOR ADVANCING AND RETRACTINGTHE SAME AXIALLY, SAID CONTROL APPARATUS COMPRISING, A GROUP OFSHIFTABLE GAUGING ELEMENTS ADAPTED TO CONTROL THE EXTENT OF SPINDLEMOTION FROM A RETRACTED POSITION, MEANS FOR SHIFTING SAID GAUGINGELEMENTS TO A SELECTED SPINDLE MEASURING POSITION, A CONTROL ELEMENTCONNECTED TO SAID SPINDLE AND MOVABLE AXIALLY IN UNISON THEREWITHRELATIVE TO SAID GAUGING ELEMENTS, SAID CONTROL ELEMENT ADAPTED TOTRANSLATE THE GAUGING ELEMENTS UPON AXIAL ADVANCEMENT OF THE SPINDLE TOAN EXTENT DETERMINED BY SAID GAUGING ELEMENTS, SAID CONTROL ELEMENTADAPTED TO DELAY THE OPERATION OF SAID SPINDLE POWER MEANS UPONTRANSLATING SAID GAUGING ELEMENTS, THEREBY TO STOP THE SPINDLE AT APREDETERMINED AXIAL POSITION, TOOL LENGTH COMPENSATING MEANSINTERCONNECTING THE SPINDLE WITH SAID CONTROL ELEMENT, AND POWER MEANSCONNECTED TO THE TOOL LENGTH COMPENSATING MEANS FOR SHIFTING SAIDCONTROL ELEMENT AXIALLY RELATIVE TO THE SPINDLE IN AN AUTOMATIC MANNER,SAID COMPENSATING MEANS ADAPTED TO VARY THE POSITION AT WHICH THESPINDLE IS STOPPED BY OPERATION OF THE GAUGING ELEMENTS IN ACCORDANCEWITH THE LENGTH OF THE TOOL WHICH IS CARRIED BY THE SPINDLE.